873 resultados para Humic acids
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BACKGROUND: The use of n-3 fatty acids may prevent cardiovascular events in patients with recent myocardial infarction or heart failure. Their effects in patients with (or at risk for) type 2 diabetes mellitus are unknown. METHODS: In this double-blind study with a 2-by-2 factorial design, we randomly assigned 12,536 patients who were at high risk for cardiovascular events and had impaired fasting glucose, impaired glucose tolerance, or diabetes to receive a 1-g capsule containing at least 900 mg (90% or more) of ethyl esters of n-3 fatty acids or placebo daily and to receive either insulin glargine or standard care. The primary outcome was death from cardiovascular causes. The results of the comparison between n-3 fatty acids and placebo are reported here. RESULTS: During a median follow up of 6.2 years, the incidence of the primary outcome was not significantly decreased among patients receiving n-3 fatty acids, as compared with those receiving placebo (574 patients [9.1%] vs. 581 patients [9.3%]; hazard ratio, 0.98; 95% confidence interval [CI], 0.87 to 1.10; P=0.72). The use of n-3 fatty acids also had no significant effect on the rates of major vascular events (1034 patients [16.5%] vs. 1017 patients [16.3%]; hazard ratio, 1.01; 95% CI, 0.93 to 1.10; P=0.81), death from any cause (951 [15.1%] vs. 964 [15.4%]; hazard ratio, 0.98; 95% CI, 0.89 to 1.07; P=0.63), or death from arrhythmia (288 [4.6%] vs. 259 [4.1%]; hazard ratio, 1.10; 95% CI, 0.93 to 1.30; P=0.26). Triglyceride levels were reduced by 14.5 mg per deciliter (0.16 mmol per liter) more among patients receiving n-3 fatty acids than among those receiving placebo (P<0.001), without a significant effect on other lipids. Adverse effects were similar in the two groups. CONCLUSIONS: Daily supplementation with 1 g of n-3 fatty acids did not reduce the rate of cardiovascular events in patients at high risk for cardiovascular events. (Funded by Sanofi; ORIGIN ClinicalTrials.gov number, NCT00069784.).
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Enhanced degradation of the fungicide metalaxyl was investigated in two soils: a gley humic (GH) and a Dark Red Latosol (LE), collected at sites never exposed to the fungicide. The soil samples were treated with successive applications of metalaxyl as a commercial formulation and 14C-metalaxyl in laboratory. Metalaxyl biodegradation was analyzed during 63 days by means of radiometric techniques to verify biomineralization and degradation product formation from the applied 14C-metalaxyl. Although biomineralization (maximum of 14 and 8% in the GH and LE soils, respectively), and partial degradation (about 32 and 48%, respectively) were detected in both soils, enhanced degradation was verified only in the GH soil. Results proved that metalaxyl behaves differently in soils.
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In most pathology laboratories worldwide, formalin-fixed paraffin embedded (FFPE) samples are the only tissue specimens available for routine diagnostics. Although commercial kits for diagnostic molecular pathology testing are becoming available, most of the current diagnostic tests are laboratory-based assays. Thus, there is a need for standardized procedures in molecular pathology, starting from the extraction of nucleic acids. To evaluate the current methods for extracting nucleic acids from FFPE tissues, 13 European laboratories, participating to the European FP6 program IMPACTS (www.impactsnetwork.eu), isolated nucleic acids from four diagnostic FFPE tissues using their routine methods, followed by quality assessment. The DNA-extraction protocols ranged from homemade protocols to commercial kits. Except for one homemade protocol, the majority gave comparable results in terms of the quality of the extracted DNA measured by the ability to amplify differently sized control gene fragments by PCR. For array-applications or tests that require an accurately determined DNA-input, we recommend using silica based adsorption columns for DNA recovery. For RNA extractions, the best results were obtained using chromatography column based commercial kits, which resulted in the highest quantity and best assayable RNA. Quality testing using RT-PCR gave successful amplification of 200 bp-250 bp PCR products from most tested tissues. Modifications of the proteinase-K digestion time led to better results, even when commercial kits were applied. The results of the study emphasize the need for quality control of the nucleic acid extracts with standardised methods to prevent false negative results and to allow data comparison among different diagnostic laboratories.
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Peroxisome proliferator-activated receptors (PPARs) are nuclear hormone receptors controlling the expression of genes involved in lipid homeostasis. PPARs activate gene transcription in response to a variety of compounds including hypolipidemic drugs as well as natural fatty acids. From the plethora of PPAR activators, Scatchard analysis of receptor-ligand interactions has thus far identified only four ligands. These are the chemotactic agent leukotriene B4 and the hypolipidemic drug Wy 14,643 for the alpha-subtype and a prostaglandin J2 metabolite and synthetic antidiabetic thiazolidinediones for the gamma-subtype. Based on the hypothesis that ligand binding to PPAR would induce interactions of the receptor with transcriptional coactivators, we have developed a novel ligand sensor assay, termed coactivator-dependent receptor ligand assay (CARLA). With CARLA we have screened several natural and synthetic candidate ligands and have identified naturally occurring fatty acids and metabolites as well as hypolipidemic drugs as bona fide ligands of the three PPAR subtypes from Xenopus laevis. Our results suggest that PPARs, by their ability to interact with a number of structurally diverse compounds, have acquired unique ligand-binding properties among the superfamily of nuclear receptors that are compatible with their biological activity.
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Introduction La maladie « Non-Alcoholic Fatty Liver Disease ; NAFLD » et l'obésité provoque la résistance à l'insuline, un symptôme caractéristique du syndrome métabolique. La fréquence de ces maladies a augmenté de manière importante durant ces dernières décennies. Cette augmentation est étroitement liée à la surcharge énergétique dans notre culture modernisée. Pour combattre cette situation, des régimes riches en protéines semblent être bénéfiques, en particulier parce que l'acide aminé leucine stimule la satiété. Cependant l'effet des protéines alimentaires sur la stéatose hépatique reste peu connu. Résultats : Pour étudier cette question, nous avons nourri des souris C57B6/J (âgées de 5 semaines) avec un régime standard (10% kcal graisse, 20% kcal protéine), un régime riche en graisse (45% kcal graisse, 20% kcal protéine) ou un régime riche en graisse et enrichi en protéines (45% kcal graisse, 40% kcal protéine) pendant 10 semaines. Nous avons ainsi montré que l'addition de protéines au régime gras permet de prévenir la stéatose hépatique. Dans un deuxième temps nous avons testé si cet effet bénéfique des protéines alimentaires provient des acides aminés ramifiés (Branched-chain amino acids= BCAA : leucine, isoleucine, valine), composants majeurs de protéines alimentaires. Pour ce faire, nous avons ajouté un groupe de souris nourries au régime riche en graisses + BCAA (45% kcal graisse, 23% kcal protéine). Nos résultats montrent que l'addition des BCAA ne protège pas contre la stéatose hépatique, mais, au contraire, aggrave l'obésité et l'hyperinsulinémie. De manière intéressante, nous avons observé que la supplémentation en protéines ou en BCAA induit des effets différents sur la prise alimentaire et la dépense énergétique. Conclusion : Notre étude suggère clairement que les protéines alimentaires protègent contre l'obésité et la stéatose hépatique. Elle confirme également que les composants majeurs des protéines alimentaires (BCAA) n'exercent pas cet effet protecteur, mais qu'il aggrave le syndrome métabolique. Etant donné que l'ingestion importante et chronique de protéines alimentaires est délétère pour le rein, il serait très intéressant d'identifier les acides aminés spécifiques qui induiraient le même effet protecteur que les protéines alimentaires, mais sans perturber le fonctionnement rénal.
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Selostus: Prosessoinnin vaikutus vehnän sivutuotteita sisältävien rehuseosten aminohappojen ohutsuolisulavuuteen sioilla
Apparent ileal digestibility of amino acids in wet wheat protein and soya bean meal for growing pigs
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Selostus: Kuivaamattoman vehnäproteiinin ja soijarouheen aminohappojen ohutsuolisulavuus sioilla
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Caveolins are a crucial component of plasma membrane (PM) caveolae but have also been localized to intracellular compartments, including the Golgi complex and lipid bodies. Mutant caveolins associated with human disease show aberrant trafficking to the PM and Golgi accumulation. We now show that the Golgi pool of mainly newly synthesized protein is detergent-soluble and predominantly in a monomeric state, in contrast to the surface pool. Caveolin at the PM is not recognized by specific caveolin antibodies unless PM cholesterol is depleted. Exit from the Golgi complex of wild-type caveolin-1 or -3, but not vesicular stomatitis virus-G protein, is modulated by changing cellular cholesterol levels. In contrast, a muscular dystrophy-associated mutant of caveolin-3, Cav3P104L, showed increased accumulation in the Golgi complex upon cholesterol treatment. In addition, we demonstrate that in response to fatty acid treatment caveolin can follow a previously undescribed pathway from the PM to lipid bodies and can move from lipid bodies to the PM in response to removal of fatty acids. The results suggest that cholesterol is a rate-limiting component for caveolin trafficking. Changes in caveolin flux through the exocytic pathway can therefore be an indicator of cellular cholesterol and fatty acid levels.
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The peroxisome proliferator-activated receptors have enjoyed the spotlight for many reasons. These transcription factors are ligand-inducible nuclear receptors that modulate gene expression in response to a broad spectrum of compounds. The recognition that PPARs are indeed nuclear receptors for polyunsaturated fatty acids, some eicosanoids and also lipid-lowering and antidiabetic drugs, has opened many exciting avenues of research and drug discovery. Recent studies on the PPAR function have extended the role of these transcription factors beyond energy homeostasis to master gene in adipogenesis and also determinants in inflammation control. While rapid advances have been made, it is clear that we are far from a global understanding of the mechanisms and functions of PPARs.
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Kinetic studies on soil potassium release can contribute to a better understanding of K availability to plants. This study was conducted to evaluate K release rates from the whole soil, clay, silt, and sand fractions of B-horizon samples of a basalt-derived Oxisol and a sienite-derived Ultisol, both representative soils from coffee regions of Minas Gerais State, Brazil. Potassium was extracted from each fraction after eight different shaking time periods (0-665 h) with either 0.001 mol L-1 citrate or oxalate at a 1:10 solid:solution ratio. First-order, Elovich, zero-order, and parabolic diffusion equations were used to parameterize the time dependence of K release. For the Oxisol, the first-order equation fitted best to the experimental data of K release, with similar rates for all fractions and independent of the presence of citrate or oxalate in the extractant solution. For all studied Ultisol fractions, in which K release rates increased when extractions were performed with citrate solution, the Elovich model described K release kinetics most adequately. The highest potassium release rate of the Ultisol silt fraction was probably due to the transference of "non-exchangeable" K to the extractant solution, whereas in the Oxisol exchangeable potassium represented the main K source in all studied fractions.
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Selostus: Väkirehuun lisätyn glyserolin tai vapaiden rasvahappojen tai näiden yhdistelmän vaikutus maidontuotantoon ja pötsifermentaatioon ruokittaessa lypsylehmiä säilörehuun perustuvalla ruokinnalla
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In the Earth's carbon cycle, C stocks in the soil are higher than in vegetation and atmosphere. Maintaining and conserving organic C concentrations in the soil by specific management practices can improve soil fertility and productivity. The aim of this study was to evaluate the impact of agricultural management techniques and influence of water regime (flooded or drained) on the structure of humic substances by excitation/emission matrix fluorescence. Six samples of a Planosol (Planossolo by the Brazilian System of Soil Classification) were collected from a rice field. Humic substances (HS) were extracted from flooded and drained soil under different agricultural management techniques: conventional tillage, reduced tillage and grassland. Two peaks at a long emission wavelength were observed in the EEM spectra of HA whereas those of the corresponding FA contained a unique fluorophore at an intermediate excitation/emission wavelength pair (EEWP) value. The fluorescence intensity measured by total luminescence (FI TL) of HA was lower than that of the corresponding FA. A comparison of all samples (i.e., the HA values compared to each other) revealed only slight differences in the EEWP position, but the FI TL values were significantly different. In this soil, anoxic conditions and reduced tillage (little plowing) seem to favor a higher degree of humification of the soil organic matter compared with aerated conditions and conventional tillage.
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Soil is the basis underlying the food production chain and it is fundamental to improve and conserve its productive capacity. Imbalanced exploitation can degrade agricultural areas physical, chemical and biologically. The objective of this study was to evaluate some soil physical properties and their relation with organic carbon contents of a Humic Dystrudept under conventional tillage (CT) and no-tillage (NT), for 12 years in rotation (r) and succession (s) cropping systems. The experiment was carried out in Lages, SC (latitude 27 º 49 ' S and longitude 50 º 20 ' W, 937 m asl), using crop sequences of bean-fallow-maize-fallow-soybean in conventional tillage rotation; maize-fallow in conventional tillage succession; bean-oat-maize-turnip-soybean-vetch in no-tillage rotation; and maize-vetch in no-tillage succession. The experimental design was completely randomized with four replications. The soil samples were collected in the layers 0-2.5, 2.5-5, 5-10, and 10-20 cm. The following properties were analyzed: soil density, porosity, aggregate stability, degree of flocculation, water retention, infiltration, mechanical strength, and total organic carbon. Soil aggregation in the surface layer (0-5 cm) was better in the no-tillage than the conventional system, related to higher microporosity, organic carbon contents and water retention capacity, indicating that a periodical tillage of this soil is unnecessary. Infiltration was highest in no-tillage with crop succession.
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Results of plasma or urinary amino acids are used for suspicion, confirmation or exclusion of diagnosis, monitoring of treatment, prevention and prognosis in inborn errors of amino acid metabolism. The concentrations in plasma or whole blood do not necessarily reflect the relevant metabolite concentrations in organs such as the brain or in cell compartments; this is especially the case in disorders that are not solely expressed in liver and/or in those which also affect nonessential amino acids. Basic biochemical knowledge has added much to the understanding of zonation and compartmentation of expressed proteins and metabolites in organs, cells and cell organelles. In this paper, selected old and new biochemical findings in PKU, urea cycle disorders and nonketotic hyperglycinaemia are reviewed; the aim is to show that integrating the knowledge gained in the last decades on enzymes and transporters related to amino acid metabolism allows a more extensive interpretation of biochemical results obtained for diagnosis and follow-up of patients and may help to pose new questions and to avoid pitfalls. The analysis and interpretation of amino acid measurements in physiological fluids should not be restricted to a few amino acids but should encompass the whole quantitative profile and include other pathophysiological markers. This is important if the patient appears not to respond as expected to treatment and is needed when investigating new therapies. We suggest that amino acid imbalance in the relevant compartments caused by over-zealous or protocol-driven treatment that is not adjusted to the individual patient's needs may prolong catabolism and must be corrected